新疆红肉苹果果皮果肉呈色差异机理

The Mechanism of Red Coloring Difference Between Skin and Cortex in Malus sieversii f.neidzwetzkyana(Dieck) Langenf.

【目的】比较新疆红肉苹果(Malus sieversii f.neidzwetzkyana(Dieck)Langenf)果皮、果肉花青苷成分、积累模式及花青苷合成相关基因的表达,以初步探明果皮、果肉呈色差异的机理。【方法】以新疆红肉苹果‘夏红肉’为试材,利用HPLC方法鉴定果皮和果肉的花青苷成分,通过QPCR测定果实着色过程中相关基因的表达,同时测定花青苷含量。【结果】果肉和果皮中花青苷的主要成分均为矢车菊素-3-半乳糖苷,但其积累模式明显不同,随着果实的发育,果皮中的花青苷含量呈下降趋势,果肉则呈相反趋势。与之对应的,花青苷合成结构基因的表达与花青苷积累模式基本一致。花青苷调控基因MsMYB10有其自身的表达特性,果皮中表达量逐渐升高,果肉中呈先升高后下降的趋势。【结论】新疆红肉苹果果皮果肉呈色差异主要与花青苷含量及其结构基因的转录表达水平有关,为进一步研究红肉苹果红色形成机理,培育具有观赏、鲜食与保健功能的苹果红肉新品种奠定了理论基础。

[Objective] The aim of this study is to explore the red development mechanism by monitoring anthocyanin composition and content, transcriptional profile of anthocyanin related genes in Malus sieversiif neidzwetzkyana （Dieck） Langenf. [Method] M. sieversiif neidzwetzkyana （Dieck） Langenfwas used as material to study anthocyanin composition of skin and cortex by HPLC, and to study the transcriptional profile of anthocyanin related genes by qPCR at four developmental stages. Anthocyanin contents in skin and cortex were determined at the four sampling times accordingly. [ Result ] Cyanidin-3-galactoside was the main anthocyanin composition of skin and cortex, but anthocyanin content had different change trends at different developmental stages. The anthocyanin content of skin showed a declined pattern, while the anthocyanin content of cortex displayed an opposite tendency. Expression of the anthocyanin biosynthesis genes was correlated with anthocyanin content： expression of MsMYBIO in skin and cortex was very high, while expression of MsMYBIO showed an increasing pattern in skin and a ＇ high-low-high-low＇ change trend in cortex during fruit development. [ Conclusion ] The red coloring difference between skin and cortex of ＇Xiahongrou＇ mainly relate to the anthocyanin content and the different expressions of anthocyanin gene. These results have provided a foundation for further exploring the red coloring mechanism and breeding cultivars of red-flesh apple.